Population pharmacokinetics of brodalumab in patients with moderate to severe plaque psoriasis.

Brodalumab is a fully human monoclonal antibody targeting the IL-17 receptor A leading to an inhibition of the biological effect of IL-17A, IL-17F, IL-17A/F heterodimer, IL-17C and IL-17E isoforms. It has shown to be efficacious in the treatment of moderate to severe plaque psoriasis (210 mg administered subcutaneously at weeks 0, 1 and 2 followed by 210 mg every 2 weeks [Q2W+1]). A population pharmacokinetic model based on psoriasis patients only from six clinical trials was developed to describe the pharmacokinetics and identify sources of variability. In patients with psoriasis, Brodalumab exhibits non-linear pharmacokinetics due to target-mediated drug disposition resulting in concentration-dependent clearance. The pharmacokinetics was best described by a two-compartment model with linear absorption and combined linear and Michaelis-Menten elimination. The subcutaneous bioavailability of Brodalumab was 55%, absorption rate was 0.30 day-1 , and body-weight was found to affect the volume of distribution and clearance. For a reference patient with plaque psoriasis (body-weight of 90 kg), the estimates were 0.16 L/d for linear serum clearance, 6.1 mg/d for the maximum non-linear clearance rate, and 4.7 and 2.4 L for central and peripheral volume of distribution, respectively. For the approved dosing regimen, time to maximum concentration was 4 days and 90% of steady-state was achieved after 10 weeks for a reference patient. Following last dose at steady-state, 90% of the population of reference patients will reach serum concentrations below lower limit of quantification after 45 days.

Pharmacokinetics of ingenol mebutate gel under maximum use conditions in large treatment areas.

PURPOSE: Actinic keratoses (AKs) exist on a continuum with squamous cell carcinoma and can occur as sub-clinical and clinically visible lesions in cancerized fields on sun-damaged skin. Ingenol mebutate effectively treats AKs on areas up to 25 cm2, but actinic keratosis can affect larger areas of skin. This trial evaluated systemic exposure and safety of ingenol mebutate gel on larger areas of skin under maximum use conditions. METHODS: Phase I, multicenter, open-label, uncontrolled, non-randomized trial. Patients received ingenol mebutate gel for three consecutive days on approximately 250 cm2 of sun-damaged skin on the full face (0.027%), the scalp (0.027%), or arm (0.06%). RESULTS: Of 61 patients, 10 (face =8; arm =2) had ingenol mebutate in whole blood at subnanomolar levels (0.235-0.462 nM). The assayed metabolites were below the lower limit of quantification. Local skin responses increased during Days 1-4 and declined thereafter, approaching baseline by Day 16. Most adverse events were pain/pruritus of mild or moderate intensity. CONCLUSIONS: Subnanomolar systemic exposure to ingenol mebutate was measured after application of the gel to approximately 250 cm2 on the full face, scalp, or arm under maximum use conditions. No clinically relevant systemic adverse reactions were observed, and local skin responses were manageable.

Pharmacokinetics and Safety of Ingenol Disoxate Gel Administered Under Maximum-Use Conditions to Patients With Actinic Keratosis.

BACKGROUND AND OBJECTIVES: Ingenol disoxate (LEO 43204) is a field therapy in development for the treatment of actinic keratosis (AK) on areas between 25 and 250 cm2. We evaluated the systemic exposure and safety of ingenol disoxate under maximum-use conditions. METHODS: This was a phase I, open-label, non-randomized, multicenter trial. Patients ≥ 18 years of age with ≥ 15 clinically typical, visible, discrete AK lesions in a treatment area on the full face or approximately 250 cm2 on the arm or scalp were treated once-daily for 3 consecutive days with ingenol disoxate 0.018, 0.1, or 0.037% gel, respectively. RESULTS: The trial included 58 patients. Median age (range) of patients was 68 years (42-89) [face, N = 18], 66 years (43-88) [arm, N = 21], and 67 years (37-83) [scalp, N = 19]. The highest quantifiable ingenol disoxate level was observed in the arm group (0.33 nM, area under the concentration-time curve from time zero to the last data point [AUCtlast] 3.12 nM·h). Mean composite local skin response scores peaked at Day 4 and declined towards baseline by Day 15 in all treatment groups. Most adverse events (AEs) were of mild or moderate intensity; the most common treatment-related AEs were application-site pain (face, 88.9%; arm, 57.1%; scalp, 100.0%) and application-site pruritus (face, 50.0%; arm, 52.4%; scalp, 42.1%). CONCLUSION: Very low systemic exposure to ingenol disoxate was observed when applied to the face, arm, or scalp in patients with AK under maximum-use conditions. No new safety signals were identified. TRIAL REGISTRATION: NCT02424305.